Báo cáo lâm nghiệp: "Timber harvesting in the ukrainian carpathians: Ecological problems and methods to solve them" ppsx

Kudra2 1Ukrainian National Forestry University, Lviv, Ukraine 2Ukrainian Research Institute for Mountain Forestry, Ivano-Frankivsk, Ukraine ABSTRACT: The paper contains results of compar

JOURNAL OF FOREST SCIENCE, 56, 2010 (7): 333–340

The Carpathians are an important part of the

ecological, economic and recreational environment

for people in the centre of Europe, shared by many

nations and countries It is one of a few regions

that preserve relatively large areas of virgin forests

with their unique fauna and flora On their basis, a

number of protected objects and territories were

created In May 2003, Ukraine signed The

Conven-tion on the ProtecConven-tion and Sustainable Development

of the Carpathians, which defines the

implemen-tation of all-round policies directed towards the

conservation and sustainable development of the

region to improve the quality of life, strengthen local

economies and communities and preserve natural

values and cultural heritage

One of the laws in force directed to more

environ-ment-friendly ways of forest utilization in Ukraine is

the Ukrainian Act on “The moratorium on

Perform-ing Clear CuttPerform-ing on Mountain Slopes in

Spruce-Beech Forests of the Carpathian Region” This law

was the first one on the state level to start using

special approaches to the organization of mountain

forestry, to introduce environmental forest

tech-nologies and to widen the network of protected

ter-ritories and also to set a number of restrictions on

the utilization of certain ways of timber cutting and certain systems of machinery

To work outparticular principles in detail and to better define the law, investigations started to deter-mine the impacts of skidders on the forest environ-ment and to work out environenviron-mental principles of timber harvesting

Current condition of mountain timber harvesting

Mountain timber harvesting is a complex, multi-step process that determines economic as well as ecological productivity of forestry The key part of this process is skidding that includes a number of factors affecting the soil surface of cutting areas either directly or indirectly Investigations started

by Ukrainian scientists unravelled these factors and determined the degree to which forest crawler and wheeled machinery influences the environment The main components of mountain timber har-vesting are the construction and running of forest roads If horses are used, this is horse portage, in the case of crawler and wheeled machinery, these are skidding tracks They are an integral part of the or-ganizational structure of primary transportation of

Timber harvesting in the ukrainian carpathians:

Ecological problems and methods to solve them

N Byblyuk1, O Styranivsky1, V Korzhov2, V Kudra2

1Ukrainian National Forestry University, Lviv, Ukraine

2Ukrainian Research Institute for Mountain Forestry, Ivano-Frankivsk, Ukraine

ABSTRACT: The paper contains results of comparative investigations of crawler and wheeled skidders regarding

their effect on soil surface, undergrowth and rut formation during mountain timber harvesting It was shown that the extent of erosion resulting from damage to the soil surface depends on the steepness and length of slopes during both construction of skidding tracks and skidding by tractors Considering the current condition of development of timber harvesting machinery, the use of crawler machines is the main method for transportation of cargos in regions with difficult access

Keywords: crawler and wheeled skidders; damage to ground surface; rut formation; undergrowth damage

timber; thus, their optimal distribution determines

the ecological efficiency of technology of

exploita-tion of the cutting area

It was stated (Byblyuk et al 2002) that tractor

skidding is the most harmful for the soil surface,

especially during the construction of skidding tracks

by a bulldozer For example, in the mountains, if

the area of skidding tracks is 8% of the total cutting

area, the volume of soil damaged by erosion often

amounts to 500 m3∙ha–1 Erosion on skidding tracks

may reach up to 70% of its total volume on the

cut-ting area The volume of soil erosion inflicted by

forest machinery is a function of the steepness and

length of a slope, degree of soil erosion vulnerability

(which in general depends on the presence of

small-size particles in soil); fraction of the area covered

by vegetation; intensity, duration, extension and

frequency of precipitation

The intensity of natural renewal of the cutting

area surface on mountain slopes and its consequent

condition significantly differ from conditions on

plains, thus, from ecological positions it is especially

important to take measures to preserve the existing

undergrowthduring timber harvesting The use of

cableway skidding system ensures the preservation

of viable undergrowthunder forest floor and allows

solving the problem of reforestationon steep slopes

The data obtained in the North Caucasus by

Rus-sian scientists (Pobedinskyy 1977) shows that in

some cases it is possible to save 80–90% of existing

undergrowth, which is 1.5–2 times more than during

primary transportation of timber by skidders

Be-sides objective factors, a significant influence on the

environment is caused by a human factor The cases

of violation of timber harvestingtechnology during

cutting are not scarce The location of undergrowth

is not always taken into account; the regulated width

of cutting, main and strip skidding tracks is not

ob-served This is caused by the absence of

responsibil-ity for violation of the ecological balance of forest ecosystems and damage inflicted to environment

In other countries, investigations on this problem have already been carried out for many years and economic stimuli to environmental forest utilization

on steep slopes have been introduced

The transport network plays an important role

in the forest industry production of mountain re-gions where forest areas are scattered in vast ter-ritories and are characterized by complex relief, soil-hydrological features, low concentration of harvested timber per unit area, one-sidedness of freight traffic volume and other factors Forest roads play an important role not only in forest utilization, renewal and preservation, but also in the general development of a region, its recreational potential, improving working conditions and well-being of the population In European countries with developed forest industry, the construction of forest roads is subsidized as a part of the state transport network Costs of the construction and maintenance of forest roads constitute there nearly one third of the total cost of harvested timber

In the Carpathian region of Ukraine, the network

of forest roads is not fully developed; its density is 4–7 times lower than in the countries of West and Central Europe Forest areas with the density of roads more than 10 m∙ha–1 constitute less than 2%

of the total forest area More than 40% of forest ter-ritories have the road density lower than 0.4 m∙ha–1

(Fig 1) This state of the transport network leads to wide utilization of primary trails of timber trans-portation in forest expanses, i.e skidding tracks, which are basic passages established without us-ing engineerus-ing structures and drainage and have rather large longitudinal inclines, which in most cases does not allow using them for the passage

of wheeled machinery skidders and tractors with cable systems The problem of selection of a type of

0

5

10

15

20

25

30

35

40

45

Fig 1 Distribution of the forest areas of the Carpathian region by presence of roads

skidder, in particular, determination of advantages

of wheeled vs crawler driving unit is urgent not

only for the mountain regions of Ukraine Table 1

summarizes results of the comparative investigation

(Matthies et al 2003) of damage intensity to the

soil surface and rootage by forest machinery with

different types of driving unitson mountain slopes

of West Europe

For all conditions of exploitation crawler

machin-ery has clear advantages regarding the degree of

damage to the soil surface But on the other hand,

wheeled machinery has an obvious advantage in

minimizing the effect on rootage For forests on

plains and slopes of medium steepness there is no

single recommendation

However, the final decision on the choice of a

skidder with either wheeled or crawler driving unit

should be based on detailed analysis of

physical-mechanical features of soil, predicted number of

passages, specific pressure of forest machine on soil

and weather conditions

MATERIAL AND METHODS

The effect of wheeled and crawler skidders on

for-est environment was evaluated by invfor-estigating the

damage to undergrowthand soil surface caused by

timber skidding and also by investigating the

proc-esses of rutformation

For the first type of investigation,

research-indus-trial plots were chosen in the mountain zones of

forest resources of five state enterprises The plots

were characterized by different natural-industrial

conditions, which allowed getting real indices of the

effect of different types of transport on the forest

The investigation of undergrowth damage was

performed on three transects located on a slope in

different sites of the cutting area, i.e in its lower,

medium and upper part (far-off end of the cutting

area) while 15–25 plots (depending on particular

conditions, e.g mosaics of renewal), 2 × 2 m each,

were established on each transect

The main parameters characterizing the effect of

timber harvesting technology on the young

gen-eration of forest are its quantitative and qualitative condition after timber cutting (Molotkov 1966; Parpan et al 1988; Kudra 2005) The quantity of undergrowthon a cutting area was determined by counting it on experimental plots and relating it to the area of 1 ha Qualitatively, undergrowth on a cutting area was divided into the following catego-ries: undamaged, weakly or greatly damaged and destructed

The effect of harvesting operations on the soil surface of cutting area was assessed complexly by investigation of the degree of damage to soil dur-ing harvestdur-ing operations and determination of plane and volumetric parameters of skidding tracks (Polyakov 1965; Oliynuk 1998) The degree of damage to soil was divided into the following cat-egories:

Zero category: There is no damage, the soil surface

is not disturbed It includes areas which were not disturbed by harvesting operations and preserve the forest floor

First category: The forest floor is loosened be-cause of the fall of trees or moving their crowns The soil is not damaged

Second category: There are plots with forest floor

removed by harvesting operations, but still preserv-ing the humus horizon The damage is mainly plain and local

Third category: There are plots with linear

dam-age in the form of primary skidding tracks (made

by one trunk) It includes single and multiple pas-sages of a tractor to the plots outside of the skidding tracks

Fourth category: There is linear-plane damage in

the form of secondary skidding tracks (damage made

by several trunks) and horse and tractor skidding tracks The third and the forth category of damage

to soil is subdivided into three categories by their depth: under 5 cm, 6–10 cm and above 10 cm

Fifth category: There are deposits, containing

small fractions of soil, leaves and stones, which are created during skidding

Field investigations of rut formation by the traffic

of wheeled and crawler tractors on forest soils were

Table 1 Recommendations for utilization of wheeled and crawler forest machinery on surface with different inclines

Surface

incline

Best results from the point of damage minimization Recommendation

for usage

~ 0° crawler harvester and wheeled or crawler forwarder wheeled machinery wheeled machinery

performed on specially selected plots in the forest

The main factors determining the effect of adriving

uniton soil are density of soil in the rut and its depth,

which depend on the number of passages in the same

track Investigations included measuring the depth

of ruts, degree of damage to the bearing surface and

soil sampling

Before the beginning of investigations the radius of

turns, lengths of linear plots, weight and geometrical

parameters of a tractor were determined Samples of

the undamaged layer of soil were taken on each plot

and at least four measuring points were established

at the distance of 1 m from each other

The following parameters were determined: soil

moisture (by weight), physical density of soil,

modu-lus of deformation, density by the difficulty of

culti-vation and depth of ruts Based on the obtained data,

plots of dependence of distribution of soil density in

the rut from the number of passages were built

RESULTS Undergrowth damage

Investigations were performed during a snowless

period on 56 experimental plots For crawler

trac-tors, the largest portion of cutting areas (41%) had

slopes of 15–20° and for wheeled tractors the most

common (34%) were plots with slopes of 10–15°

The obtained results of investigations (Fig 2)

demonstrate that using crawler tractors for timber

harvesting preserves on average 85.1% of

under-growth and using wheeled tractors preserves 84.4%

of undergrowth This percentage depends on many

factors, including the season of harvesting,

steep-ness of slope, position of skidding tracks etc., and varies between 50.0% and 99.5% By the portion of undamaged undergrowth we mean the degree of its preservation on areas undisturbed by skidding tracks But practically all undergrowth is destroyed

on the skidding tracks because they are prepared before cutting Thus, it can be considered that the portion of a plot occupied by skidding tracks is free

of undergrowth and after timber harvesting it should

be a subject for reforestation

There is no significant difference in the degree of damage caused by crawler and wheeled tractors be-cause these forest machines perform identical opera-tions during timber collection and skidding

The intensity of undergrowth damage by skidders

by categories is shown in Table 2 For both types of tractors the prevalent types of damage are peeling of trunks (46.2% and 57.1%) and weak or strong damage

to rootage (19.1% and 23.1%) that is caused by the movement of trunks or tractors

5

6.4

3.5 2.9

6.8

2.9

0 1 2 3 4 5 6 7 8

Weakly damaged

Greatly damaged

Destructed

Crawler skidder Wheeled skidder

Fig 2 Distribution of undergrowth damage by categories

Table 2 Average numbers of damaged undergrowth – Type and magnitude of damage, thousands per 1 ha (%)

Crown damage Fracture of top Peeling of bark Fracture of trunk Roots damage Skidding by crawler tractors

Skidding by wheeled tractors

Table 3 Average characteristics of skidding ways on research plots

Type of skidder Length of skidding ways (m∙ha–1) width (m)Average (mArea 3∙ha–1) % of cutting area skidding ways (mSoil erosion volume on 3∙ha–1)

Damage to soil surface

During the investigation of damage to the soil

surface of mountain cutting area, the main features

(extent, average width, area and volume of

opera-tional erosion) of skidding tracks used for the traffic

of wheeled and crawler machinery were determined

(Table 3) Their analysis suggests that the density

of skidding track network and portion of the area

they occupy in cutting areasdeveloped by wheeled

tractors is almost 10% larger than in cutting area

de-veloped by crawler tractors This is explained by the

existing limitations of slopes where wheeled tractors

can be used and related necessity of laying a greater

number of skidding tracks

On average, on the investigated cutting areas,

skid-ding tracks take up 5.2% of cutting area if crawler

tractors are used, and 5.1% if wheeled tractors are

used, which is basically the same number The

vol-umes of soil erosion caused by skidding tracks are

220 and 169 m3∙ha–1, respectively

In the case of tractor skidding,around 80% of the

cutting area is left undamaged; the difference between

wheeled and crawler tractors does not exceed 0.5%

The plots with mineralized surface, i.e those where

the forest floor is partly mixed with mineral particles of soil, constitute 9.3% of the total cutting area if crawler tractors are used, which is 1.5 times more than for wheeled tractors But from the forestrypoint of view, mineralized plots play a positive role because they as-sist in the natural renewal of forests, especially in the case of unclear cutting The average volume of soil erosion, taking into account skidding tracksand areas outside of skidding tracks is 264 m3∙ha–1 if crawler tractors are used and 240 m3∙ha–1 if wheeled tractors are used The difference is in the range of 10% Comparative data on damage to the soil surface on

a cutting areawhere wheeled and crawler tractors are used is shown in Fig 3

Intensity of rut formation

Features of plots used as the proving ground for the investigation of rut formation are shown in Table 4 Results of the investigation and photographs of indi-vidual stages of measuring are shown in Figs 4–6 Analysis of the obtained graphical dependences allowed drawing the following conclusions:

– The intensity of rut formation significantly de-pends on the bearing capacity of soil, which is

9.3

2.5

2

6.3

1.1

6.3

6.8

1.7 0

1

2

3

4

5

6

7

8

9

10

Mineralized Damage less

than 5 cm

Damage 6–10 cm

Damage more than 10 cm

Deposits

Crawler skidder Wheeled skidder

Fig 3 Comparative data on the soil surface damage

Table 4 Characteristics of test plots

Plot No Object of investigation; load Description and transversal incline of the area Primary parameters of soil

density (g∙cm –3 ) humidity (%)

covered by dense vegetation, 9° 0.65–0.99 70–81

3 ТТ-4; 1 (t) frozen soil with broken stone, compressed by branches, 0° 1.30–1.55 43–55

4 LKT-81; 0.7 (t) covered with dense vegetation, well-ventilated, 7° 0.71–1.08 42–51

5 TDT-55А; 1.56 (t) well-moistened and compressed with branches, 2° 1.18–1.49 32–61 TAF-657; 1.12 (t)

y = 4.4483ln(x) –

0.5477

y = 2.57ln(x) –

0.6443 0

2 4 6 8 10 12

Passages without branches with branches

y = 1.900ln(x) + 0.344

y = 4.706ln(x) + 0.876

0 2 4 6 8 10 12 14

Passages

y = 0.108ln(x) + 1.327

y = 0.213ln(x) + 1.408

1.3 1.5 1.7 1.9

3 )

Passages Straight motion

y = 4.4483ln(x) –

0.5477

y = 2.57ln(x) –

0.6443 0

2 4 6 8 10 12

Passages without branches with branches

y = 1.900ln(x) + 0.344

y = 4.706ln(x) + 0.876

0 2 4 6 8 10 12 14

Passages

y = 0.108ln(x) + 1.327

y = 0.213ln(x) + 1.408

1.3 1.5 1.7 1.9

3 )

Fig 5 Investigation of the interaction of crawler skidder TDT-55A with bearing surface (plot 2)

y = 4.4483ln(x) –

0.5477

y = 2.57ln(x) –

0.6443 0

2 4 6 8 10 12

Passages without branches with branches

y = 1.900ln(x) + 0.344

y = 4.706ln(x) + 0.876

0 2 4 6 8 10 12 14

Passages

y = 0.108ln(x) + 1.327

y = 0.213ln(x) + 1.408

1.3 1.5 1.7 1.9

3 )

Passages Straight motion turn with minimal radius

–3 )

y = 4.4483ln(x) –

0.5477

y = 2.57ln(x) –

0.6443 0

2 4 6 8 10 12

Passages without branches with branches

y = 1.900ln(x) + 0.344

y = 4.706ln(x) + 0.876

0 2 4 6 8 10 12 14

Passages

y = 0.108ln(x) + 1.327

y = 0.213ln(x) + 1.408

1.3 1.5 1.7 1.9

3 )

Passages Straight motion

y = 2.2275ln(x) –

0 8165 8

1.4316 15

20 0.8165

y = 0.985ln(x) + 0.511

0 2 4 6

y = 2.2275ln(x) –

0.8165 0

5 10 15

Passages without branches with branches

Passages turn with a minimal radius Straight motion

y = 0.247ln(x) + 0.636

1.4 1.6

y = 0.168ln(x) + 0.714

0.6 0.8 1.0 1.2

3 )

Passages

y = 2.2275ln(x) –

0 8165 8

1.4316 15

20 0.8165

y = 0.985ln(x) + 0.511

0 2 4 6

y = 2.2275ln(x) –

0.8165 0

5 10 15

Passages without branches with branches

Passages turn with a minimal radius Straight motion

y = 0.247ln(x) + 0.636

1.4 1.6

y = 0.168ln(x) + 0.714

0.6 0.8 1.0 1.2

3 )

Passages

Fig 4 Investigation of the interaction of wheeled skidder LKT-81 with bearing surface (plot 1)

y = 2.2275ln(x) –

0 8165 8

1.4316 15

20 0.8165

y = 0.985ln(x) + 0.511

0

2

4

6

y = 2.2275ln(x) –

0.8165 0

5 10 15

Passages without branches

with branches

Passages turn with a minimal radius Straight motion

y = 0.247ln(x) + 0.636

1.4

1.6

y = 0.168ln(x) + 0.714

0.6

0.8

1.0

1.2

3 )

Passages

–3 )

y = 4.5179ln(x) – 1.4316

y = 2.22751ln(x) – 0.8165

y = 4.4483ln(x) –

0.5477

y = 2.57ln(x) –

0.6443 0

2 4 6 8 10 12

Passages without branches with branches

y = 1.900ln(x) + 0.344

y = 4.706ln(x) + 0.876

0 2 4 6 8 10 12 14

Passages

y = 0.108ln(x) + 1.327

y = 0.213ln(x) + 1.408

1.3 1.5 1.7 1.9

3 )

Passages Straight motion

y = 2.22751ln(x) – 0.8165

y = 4.4483ln(x) –

0.5477

y = 2.57ln(x) –

0.6443 0

2 4 6 8 10 12

Passages without branches with branches

y = 1.900ln(x) + 0.344

y = 4.706ln(x) + 0.876

0 2 4 6 8 10 12 14

Passages

y = 0.108ln(x) + 1.327

y = 0.213ln(x) + 1.408

1.3 1.5 1.7 1.9

3 )

Passages Straight motion

y = 2.571ln(x) – 0.6443

y = 4.4483ln(x) – 0.5477

y = 4.4483ln(x) –

0.5477

y = 2.57ln(x) –

0.6443 0

2 4 6 8 10 12

Passages without branches with branches

y = 1.900ln(x) + 0.344

y = 4.706ln(x) + 0.876

0 2 4 6 8 10 12 14

Passages

y = 0.108ln(x) + 1.327

y = 0.213ln(x) + 1.408

1.3 1.5 1.7 1.9

3 )

Passages Straight motion

determined by the geomorphologic structure of the Carpathians to a considerable extent

– The most intense compression of soil occurs dur-ing the first several passages (around 70% of the rut depth)

– The existence of a floorof branches significantly (2–3 times) decreases the depth of a rut and also decreases the intensity of soil compression by 10–20% A larger decrease in the degree of dam-age is typical of the crawler driving unit

– At turns with minimal radius the depth of ruts

increases 1.5–2 times for wheeled tractor and

2–3 times for crawler tractor as compared with

linear movement

– Soil compression by wheeled and crawler tractors

during linear movement occurs practically by the

same dependences

– Greater damage to the soil surface with high

bear-ing capacity is typical of crawler tractors while

wheeled tractors cause greater damage to the

surface with low bearing capacity

CONCLUSIONS

The effect of technological processes and systems

of machines used in mountain forests on the forest

environment significantly depends on the way of

primary transportation of timber and transportation

network in forests

The greatest damage to the forest environment

(soil, undergrowth, forest) is inflicted during soil

transportation of timber while using either crawler

or wheeled tractors moving by elementary passages

(skidding tracks) From this position, cut of length

timber harvesting has clear advantage It includes

primary transportation of timber by forwarders and

thus eliminates the possibility of damage to the soil

surface by timber

The highest volume of soil erosion (~70–80 %) is

inflicted by shifting the soil while establishing

skid-ding tracks which are the main cause of further

ero-sion after the end of timber harvesting operations

The volume of erosion resulting from damage to

the soil surface during preliminary establishment of

skidding tracks as well as skidding by tractors

sig-nificantly depends on the steepness of a slope and

its length (the degree of erosion is approximately

proportional to double steepness of a slope in %)

The intensity of damage to the bearing surface depends on parameters of soil in the rut of skidding tracks, weather conditions during the works, number

of passages and specifics of the construction of a skidder:

– With an increase in the number of passages the degree of soil damage grows logarithmically; – Soil compression leads to a decrease in its humid-ity and softness and an increase in denshumid-ity thick-ness and shear strength;

– The damage to the bearing surface reversely de-pends on the degree of soil freezing;

– The presence of branch floor decreases the depth

of ruts, especially on soils with undamaged struc-ture (2–4 times);

– Crawler and wheeled tractors on loamy soils compress the bearing surface approximately to the same extent

There are practically no differences in

under-growth damage inflicted by crawler or wheeled

trac-tors because during timber collectionand skidding the extraction by these machines performs practi-cally the same operations

At the current stage of development of timber harvesting machinery, the main method to solve problems of cargo transportation in regions difficult

to access is the utilization of a system of machines using the crawler driving unit

Technological processes of timber harvesting have

to be based on the optimal combination of different types of special forest machinery, depending on spe-cific natural-industrial conditions, with obligatory preliminary construction of forest roads and ensur-ing the optimal distances of primary transportation

of timber

One of the main methods to decrease the negative influence of primary timber transportation is the uti-lization of cable transport systems on steep slopes Fig 6 Investigation of the interaction of wheeled TAF657 and crawler TT4 skidders with bearing surface (plot 5)

Byblyuk N., Styraninsky O., Byblyuk M., Boyko M.,

Schupak A (2002): Methodical approaches to the

improve-ment of technology of mountain harvesting taking into

account environmental requirements Naukovyy visnyk

Natsionalnogo agrarnogo universytetu, 54: 128–137 (in

Ukrainian)

Kudra V S (2005): To the method of estimation of success

of the forest renewal In: Proceedings of International

Scientific Conference Scientific Bases of Sustainable Forest

Management Ivano-Frankivsk: 157–160 (in Ukrainian)

Matthies D., Wolf B., Kremer J., Ohrner G (2003):

Com-parative study of the impact of wheeled and tracked forest

machines on soil and roots In: Proceedings Austro 2003

– High Tech Forest Operations for Mountainous Terrain

5.–9 October 2003 Schlaegl, Austria University of Natural

Resources and Applied Sciences Vienna CD-ROM: 1–8

Molotkov P I (1966): The beech forests and management of them Moskva, Lesnaya promyshlennost: 123 (in Russian) Parpan V I., Makovskyy G M., Oliynyk V S., Oleneva-Antoshenko l S., Kydra V S (1988): Recommendations

on perfection of forest renewal in the oak and beech forests

of Carpathians at modern harvesting technologies Ivano-Frankovsk, Karpatskiy filial UkrNIILHA: 16 (in Russian) Oliynyk V S (1998): Classification of soil damages during harvesting in Carpathians Naukovyy visnyk Chernivet-skogo universytetu Chernivtsi: 13–20 (in Ukrainian) Pobedinskyy A V (1977): Studying of Forestry Processes Moskva, Nauka: 62 (in Russian)

Polyakov A F (1965): Influence of Main Cutting on

Soil-Protective Properties of the Beech Forests Moskva, Lesnaya promyshlennost: 174 (in Russian)

Received for publication: November 11, 2009 Accepted after corrections: February 13, 2010

Corresponding author:

Assoc Prof Oleg Styranivsky, Ukrainian National Forestry University, General Chuprynka str 103,

79057 Lviv, Ukraine

tel.: + 380 322 392 769, fax: + 380 322 378 905, e-mail: styranivsky@ukr.net